SU1286247A1 - Apparatus for automatic control of filter press operation - Google Patents

Abstract

A device for automatic control of filter presses operation comprises a control unit which is connected through the filtrate conduit (2) to at least one filter press and which consists of a tube (4) connected to the conduit (2) and provided at its lower end with a transverse partition (7) with a gauged hole (7'). The control unit contains a sensor (3) consisting of an electrocapacitive element connected, through a converter (14) and a switch (15), to a time counting unit (8) which is connected, in its turn, to a frequency coincidence unit (17) fed from a frequency generator (19), and to units (9) and control desks (11) of filter presses. The unit (9) and the control desk (11) of each filter press are interconnected whereas the control output of each control desk (11) is connected to an actuating mechanism of the corresponding filter press (1).

Description

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The invention relates to devices for automatic control of the process of sludge dewatering on filter presses and can be used for dewatering sewage sludge in the chemical, pulp and paper, metallurgical and other industries.

The aim of the invention is to improve the performance of filter presses.

The drawing shows a schematic diagram of an automatic control device.

The device contains a filter press 1, a filtrate collector 2, a filtrate pipeline 3, a replaceable washer 4 with a calibrated orifice, a funnel 5, a filtrate discharge line 6 to drainage, an electro-capacitive sensor 7 for breaking a liquid jet, a converter 8, a contactor 9, a frequency converter 10, the first pulse generator 11, frequency matching unit 12, second pulse generator 13, adder 14, operation time setting unit 15, filter press control pulp 16 and contactor 17.

The automatic control device operates as follows.

The operator, before starting work, selects any working filter press 1 from the group, closes the contactors 9 and 17 of the corresponding filter press 1 and puts it into operation.

When separating the solid and liquid phases of the suspension on the filter press 1, the filtrate from it enters the collector 2 of the filtrate. From the filtrate collector 2, part of the filtrate flows through the filtrate pipeline 3. The cross section of the calibrated orifice of the washer 4 is chosen so that the flow rate of the filtrate through it corresponds to the desired humidity of the precipitate during pressing or optimum filling of the chambers of the filter press 1 during filtering. Therefore, in the initial period of the sedimentation dewatering operation, the flow of filtrate will be greater than the flow through the calibrated orifice of the washer 4 ,, and the filtrate through the collector 2 will flow in a continuous stream. Pass through the calibrated orifice of the washer 4, the filtrate enters the funnel 5 and the filtrate discharge pipe 6.

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In this case, the electrical capacitance of the sensor 7 will have a constant value, the output signal of the converter 8 will have a constant level, and the output of the frequency converter 10 will generate constant frequency pulses entering the frequency matching unit 12.

Simultaneously with the inclusion of the filter press 1 in operation, a closed contactor 17 is supplied with power to the converter 10 hours 10, the first pulse generator 11, the second generator 13 (minute) pulses, and the adder 14.

With a continuous flow of filtrate through the collector 2, the frequencies of the output pulses of the frequency converter 10 and the first generator of the 11 pulses are different and there is no signal coincidence at the output of block 12. The 13 minute pulse generator generates pulses, which are summed by the adder 14.

20 At the moment when the flow rate of the filtrate through the calibrated orifice of the plate 4 becomes greater than the flow rate of the filtrate from the filter press 1, the liquid stream in the collector 2 of the filtrate is broken. In this case, the electrical capacitance of the sensor 7 will change, in turn, the level of the output current of the converter 8 and the frequency of the output pulses of the frequency converter 0 will change. The frequency of the pulses of the generator and pulses is set to

on the frequency of the jet break and when the frequencies of the first generator 11 pulses and frequency converter 10 coincide, the frequency matching block 12 generates a signal to stop the operation and turn off the second generator of 13 (minute) pulses, which will correspond to a given humidity of the sludge being unloaded from the filter press 1 .

The remaining filter presses of group 1 operate according to the mode of the control filter press 1.

Before starting the operation automatically

 The operation duration is set by the units 15 for each of the filter presses 1. After each operation of the control filter press 1, the units 15 of the operation time setting are adjusted, with the result that all the filter presses operate in a mode;

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Claims (1)

DEVICE FOR AUTOMATIC CONTROL OF FILTER PRESS OPERATION, containing on each of the filter presses filtrate collectors and electrical capacitive sensors associated with converters, characterized in that, in order to increase the performance of filter presses, the device further comprises a filtrate pipeline with replaceable washers having calibrated> holes , and units for setting the duration of operations with remotes installed on each of the filter presses, as well as a frequency converter, a first pulse generator, a unit with frequency incidence and a second pulse generator, an adder, while an electrical capacitive sensor of each filter press is installed in the filtrate pipeline, the outputs of the converters are connected through the frequency converter to the first input of the frequency matching unit, the second input of which is connected to the output of the first pulse generator, and the output through the second generator - § torr and pulse adder coupled to bloka- ^w E installation operations duration / each filter presses. * 1286247 A1